This invention relates generally to optically-based bar code symbol reading systems, and more particularly to an automatic bar code symbol reading system having a laser scanning engine with novel control circuitry.
Various types of optical scanners are in use and have been disclosed in the relevant literature. Many of these scanners read bar codes, such as the Uniform Produce Code (UPC), which are imprinted on products, labels affixed to products, or packaging for products.
One type of existing scanner is referred to as a slot scanner. Typically, slot scanners are mounted beneath or at the checkout counter of a retail establishment, such as a supermarket. Another type of scanner is a hand-held scanner. This type of scanner typically includes a grip portion held in one""s hand to enable the scanner to be directed onto a bar code so that the scan pattern produced by the scanner traverses the bar code symbol in order to read it.
In the last few years there has been increased development toward making hand-held scanners extremely small and lightweight. One such scanner is disclosed in my U.S. Pat. No. 4,930,848, which disclosure is incorporated by reference, and which is assigned to the Assignee of the present invention. That scanner comprises a hand grip portion and a body portion. Within the body portion of the scanner is an xe2x80x9claser scanning enginexe2x80x9d having all of the necessary optical, mechanical and electrical components required to produce a laser beam scanning pattern for reading bar codes and for receiving light reflected therefrom to produce an electrical signal indicative thereof. Other hand-held laser scanners are disclosed in the patent literature, including U.S. Pat. Nos. 4,387,297 (Swartz, et al.), U.S. Pat. No. 4,409,470 (Swartz, et al.), U.S. Pat. No. 4,460,120 (Swartz, at al.), U.S. Pat. No. 4,607,156 (Koppenall, et al.). U.S. Pat. No. 4,706,248 (Swartz, et al.), and U.S. Pat. No. 4,575,625 (Knowles).
Although prior art hand-held scanners are capable of reading bar code symbols, they all typically require that they be held in the hand of the user so that the laser beam scanning pattern can be aimed at the bar code symbol. In the course of checking out customers"" purchases at a checkout counter, a clerk is thus required to continually pick up the scanner, direct its laser beam onto the symbols to effect the reading of the symbols, and then either lay down the scanner between readings or between customers or place it in a support cradle or mount so that the clerk can use his or her hands for other purposes.
Thus, there is a great need in the art for a bar code symbol reading system that offers the features of a hand-held system, while enabling hands-free triggerless operation.
Accordingly, a general object of the present invention is to provide an automatic bar code symbol reading system having a laser scanning engine of compact, lightweight construction, and which overcomes the disadvantages of prior art systems.
It is a further object of the present invention to provide a compact, lightweight bar code symbol reading system which allows the hands of the user to be free when the scanner is in use.
It is still a further object of this invention to provide a compact, lightweight bar code symbol reading system having a small laser scanning engine mountable to the body of the user for producing a laser scanning pattern during hands-free operation.
It is still a further object of this invention to provide a bar code symbol reading system having a portable or body mountable laser scanning engine which is connected to a processing unit which may be mounted on the body of the user or on some other structure.
It is still another further object of this invention to provide a compact, lightweight bar code symbol reading system which is portable or body-mountable and which automatically initiates operation of the laser scanner engine when the laser scanner engine is brought close to an object with a coded symbol to be read.
These and other objects of the subject invention are achieved by providing an automatic bar code symbol reading system for reading coded symbols, e.g., UPC symbols, etc.
In the illustrative embodiment, the system comprises a laser scanning engine for producing a laser scanning pattern and a remote unit coupled thereto. The laser scanning engine includes a mounting/conveying mechanism for: (a) mounting the scanning engine on the body of the user, e.g., on the wrist, head, etc, and/or (b) for conveying the scanning engine from place to place. The user may position the laser scanning engine on his or her body so that the laser scanning pattern produced thereby is directed toward and traverses the coded symbol to be read. The laser scanning engine is operably connected to the remote unit via a communications mechanism. In the illustrative embodiment, the remote unit includes electrical means for processing and decoding the signals received from the laser scanning engine and producing symbol character data representative of the symbols read. The remote unit may be also mounted on the body of the user or on some stationary support.